Ocean Circulation and Climate Dynamics

Physical processes in upwelling regions

  
Meso- and submesoscale variability in tropical upwelling regimes

Tropical upwelling regimes are characterized by pronounced meso- and submesoscale variability such as eddies and filaments. Understanding these phenomena is crucial as they cause horizontal and vertical fluxes of mass, heat and solutes such as nutrients and oxygen. Additionally strong physical-­biogeochemical coupling exists at the associated scales. However, the high temporal and spatial variability of these processes poses a large challenge to observational studies.

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Figure 1: The sea surface temperature (SST) in the Peruvian upwelling regime observed by MODIS Aqua with 1 km horizontal resolution is shown on the left. A zoom into the near-surface temperature field associated with a submesoscale filament observed by a glider is shown on the right. (Thomsen et al. 2016).

  

Multi-platform observations and adaptive sampling

High-resolution multi­platform (ship, gliders and moorings) observations are used to study meso- and submesoscale variability off Peru and Mauritania.

The ship­based sampling is guided by the glider observations, which are accessed in near­real time via satellite. This adaptive sampling strategy allows us to target the physical­-biogeochemical coupling in specific phenomena such as eddies or filaments.

Figure 2: Three dimensional temperature field off Peru observed between February 12-17 2013 by multiple glider and shipboard observations. The glider data is sent in near­real time via satellite to GEOMAR and is directly accessible on board via internet.